Serial Communication Link Malfunction
The powertrain control module (PCM) is having issues communicating on the serial communication network.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine computer is not able to talk to other computers in the vehicle, which could cause various performance issues or warning lights.
What the computer is actually seeing
The PCM detects an abnormal condition in the communication circuit, not receiving expected data packets from other modules.
What a healthy reading looks like
Data packets should be transmitted accurately at 10-200 Kbps between modules without errors.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors for damaged or corroded connections between the PCM and other modules. (Decision: Repair any faults? Yes: Proceed; No: Next Step)
- 22. Check for any blown fuses related to the PCM or communication circuits. (Decision: Replace any blown fuses? Yes: Test; No: Next Step)
- 33. Use a scan tool to check for additional codes; make a note of any related codes. (Decision: Are there additional codes? Yes: Troubleshoot those; No: Next Step)
- 44. Test the power and ground signals at the PCM's connectors. Power should be around 12V and ground should be below 0.5 ohms. (Decision: Is power and ground okay? Yes: Replace PCM; No: Repair the wiring)
- 55. If all tests are good, replace the PCM. Reflash or program the new unit as required.
Common causes
- Faulty PCM
- Damaged wiring harness
- Poor connectors
- Failed communication module
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive; you could lose engine control or performance.
Will this code come back after fixing?
If the underlying issue is resolved, it shouldn't come back.
Why does this code pair with others?
It often indicates multiple communication failures in different modules.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →